Surely people would be talking about this on the internet if it were true.

The part about a Russian fighter doing it seems highly unlikely. AFAIR, a Russian fighter hasn't shot down an American plane since the Korean War, and even Stalin had the prudence to have the Russian pilots fly North Korean planes and take cyanide if they were about to be captured.

I can see Russian advisers firing SAMs, since there's plausiable deniability there.